Wrap api search test in skip wrapper

If the search method returns an timeout, such as in [1], the build fails. This
changes the behavior, and marks the test as 'skipped'. Non-timeouts will
still cause the build to fail.

[1] https://travis-ci.org/wikimedia/pywikibot-core/builds/11205092

Change-Id: I59b2c576e156c3896c7b1743c7d046af7386834b
Merge "Wrap api search test in skip wrapper"